Search Results: "pm"

27 September 2014

Ritesh Raj Sarraf: Laptop Mode Tools 1.66

I am pleased to announce the release of Laptop Mode Tools at version 1.66. This release fixes an important bug in the way Laptop Mode Tools is invoked. Users, now when disable it in the config file, the tool will be disabled. Thanks to bendlas@github for narrowing it down. The GUI configuration tool has been improved, thanks to Juan. And there is a new power saving module for users with ATI Radeon cards. Thanks to M. Ziebell for submitting the patch. Laptop Mode Tools development can be tracked @ GitHub

AddThis:
Share page with AddThis

Categories:

Keywords:

25 September 2014

Aigars Mahinovs: Distributing third party applications via Docker?

Recently the discussions around how to distribute third party applications for "Linux" has become a new topic of the hour and for a good reason - Linux is becoming mainstream outside of free software world. While having each distribution have a perfectly packaged, version-controlled and natively compiled version of each application installable from a per-distribution repository in a simple and fully secured manner is a great solution for popular free software applications, this model is slightly less ideal for less popular apps and for non-free software applications. In these scenarios the developers of the software would want to do the packaging into some form, distribute that to end-users (either directly or trough some other channels, such as app stores) and have just one version that would work on any Linux distribution and keep working for a long while. For me the topic really hit at Debconf 14 where Linus voiced his frustrations with app distribution problems and also some of that was touched by Valve. Looking back we can see passionate discussions and interesting ideas on the subject from systemd developers (another) and Gnome developers (part2 and part3). After reading/watching all that I came away with the impression that I love many of the ideas expressed, but I am not as thrilled about the proposed solutions. The systemd managed zoo of btrfs volumes is something that I actually had a nightmare about. There are far simpler solutions with existing code that you can start working on right now. I would prefer basing Linux applications on Docker. Docker is a convenience layer on top of Linux cgroups and namespaces. Docker stores its images in a datastore that can be based on AUFS or btrfs or devicemapper or even plain files. It already has a semantic for defining images, creating them, running them, explicitly linking resources and controlling processes. Lets play a simple scenario on how third party applications should work on Linux. Third party application developer writes a new game for Linux. As his target he chooses one of the "application runtime" Docker images on Docker Hub. Let's say he chooses the latest Debian stable release. In that case he writes a simple Dockerfile that installs his build-dependencies and compiles his game in "debian-app-dev:wheezy" container. The output of that is a new folder containing all the compiled game resources and another Dockerfile - this one describes the runtime dependencies of the game. Now when a docker image is built from this compiled folder, it is based on "debian-app:wheezy" container that no longer has any development tools and is optimized for speed and size. After this build is complete the developer exports the Docker image into a file. This file can contain either the full system needed to run the new game or (after #8214 is implemented) just the filesystem layers with the actual game files and enough meta-data to reconstruct the full environment from public Docker repos. The developer can then distribute this file to the end user in the way that is comfortable for them. The end user would download the game file (either trough an app store app, app store website or in any other way) and import it into local Docker instance. For user convenience we would need to come with an file extension and create some GUIs to launch for double click, similar to GDebi. Here the user would be able to review what permissions the app needs to run (like GL access, PulseAudio, webcam, storage for save files, ...). Enough metainfo and cooperation would have to exist to allow desktop menu to detect installed "apps" in Docker and show shortcuts to launch them. When the user does so, a new Docker container is launched running the command provided by the developer inside the container. Other metadata would determine other docker run options, such as whether to link over a socket for talking to PulseAudio or whether to mount in a folder into the container to where the game would be able to save its save files. Or even if the application would be able to access X (or Wayland) at all. Behind the scenes the application is running from the contained and stable libraries, but talking to a limited and restricted set of system level services. Those would need to be kept backwards compatible once we start this process. On the sandboxing part, not only our third party application is running in a very limited environment, but also we can enhance our system services to recognize requests from such applications via cgroups. This can, for example, allow a window manager to mark all windows spawned by an application even if the are from a bunch of different processes. Also the window manager can now track all processes of a logical application from any of its windows. For updates the developer can simply create a new image and distribute the same size file as before, or, if the purchase is going via some kind of app-store application, the layers that actually changed can be rsynced over individually thus creating a much faster update experience. Images with the same base can share data, this would encourage creation of higher level base images, such as "debian-app-gamegl:wheezy" that all GL game developers could use thus getting a smaller installation package. After a while the question of updating abandonware will come up. Say there is is this cool game built on top of "debian-app-gamegl:wheezy", but now there was a security bug or some other issue that requires the base image to be updated, but that would not require a recompile or a change to the game itself. If this Docker proposal is realized, then either the end user or a redistributor can easily re-base the old Docker image of the game on a new base. Using this mechanism it would also be possible to handle incompatible changes to system services - ten years down the line AwesomeAudio replaces PulseAudio, so we create a new "debian-app-gamegl:wheezy.14" version that contains a replacement libpulse that actually talks to AwesomeAudio system service instead. There is no need to re-invent everything or push everything and now package management too into systemd or push non-distribution application management into distribution tools. Separating things into logical blocks does not hurt their interoperability, but it allows to recombine them in a different way for a different purpose or to replace some part to create a system with a radically different functionality. Or am I crazy and we should just go and sacrifice Docker, apt, dpkg, FHS and non-btrfs filesystems on the altar of systemd? P.S. You might get the impression that I dislike systemd. I love it! Like an init system. And I love the ideas and talent of the systemd developers. But I think that systemd should have nothing to do with application distribution or processes started by users. I am sometimes getting an uncomfortable feeling that systemd is morphing towards replacing the whole of System V jumping all the way to System D and rewriting, obsoleting or absorbing everything between the kernel and Gnome. In my opinion it would be far healthier for the community if all of these projects would developed and be usable separately from systemd, so that other solutions can compete on a level playing field. Or, maybe, we could just confess that what systemd is doing is creating a new Linux meta-distribution.

Petter Reinholdtsen: Suddenly I am the new upstream of the lsdvd command line tool

I use the lsdvd tool to handle my fairly large DVD collection. It is a nice command line tool to get details about a DVD, like title, tracks, track length, etc, in XML, Perl or human readable format. But lsdvd have not seen any new development since 2006 and had a few irritating bugs affecting its use with some DVDs. Upstream seemed to be dead, and in January I sent a small probe asking for a version control repository for the project, without any reply. But I use it regularly and would like to get an updated version into Debian. So two weeks ago I tried harder to get in touch with the project admin, and after getting a reply from him explaining that he was no longer interested in the project, I asked if I could take over. And yesterday, I became project admin. I've been in touch with a Gentoo developer and the Debian maintainer interested in joining forces to maintain the upstream project, and I hope we can get a new release out fairly quickly, collecting the patches spread around on the internet into on place. I've added the relevant Debian patches to the freshly created git repository, and expect the Gentoo patches to make it too. If you got a DVD collection and care about command line tools, check out the git source and join the project mailing list. :)

24 September 2014

Vincent Sanders: I wanted to go to Portland because it's a really good book town.

Plane at Heathrow terminal 5 taking me to America for Debconf 14Patti Smith is right, more than any other US city I have visited, Portland feels different. Although living in Cambridge, which sometimes feels like where books were invented, might give me a warped sense of a place.

Jo McIntyre getting on the tram at PDX
I have visited Portland a few times previously and I feel comfortable every time I arrive at PDX. Sure the place still suffers from the american obsession with the car but similar to New York you can rely on public transport to get about.

On this occasion my visit was for the Debian Conference which i was excited to attend having missed the previous one in Switzerland. This time the conference has changed its format to being 10 days long and mixing the developer time in with the more formal sessions.

The opening session gave Steve McIntyre and myself the opportunity to present a small token of our appreciation to Russ. The keynote speakers that afternoon were all very interesting both Stefano Zacchiroli and Gabriella Coleman giving food for thought on two very different subjects.

The sponsored accomodation rooms were plesent
Several conferences in the past have experienced issues with sponsored accommodation and food, I am very pleased to report that both were very good this time. The room I was in had a small kitchen area, en-suite bathroom, desks and most importantly comfortable beds.

Andy and Patty in the Ondine dining area
The food provision was in the form of a buffet in the Ondine facility. The menu was not greatly varied but catered to all requirements including vegetarian and gluten free diets.

Neil, Rob, Jo, Steve , Neil, Daniel and Andy dining under the planes
Some of us went on a visit to the Evergreen air and space museum to look at some rare aircraft and rockets. I can thoroughly recommend a visit if you are in the area.

These are just the highlights of the week though, the time in the hack-labs was productive with several practical achievements Including:
- Uploading new packages reducing the bug count
- Sorting out getting an updated key into the Debian keyring.

Overall I had a thoroughly enjoyable time and got a lot out of the conference this year. The new format suited me surprisingly well and as usual the social side was as valuable as the practical.

I hope the organisers have recovered enough to appreciate just how good a job they did and not get hung up on the small number of things that went wrong when the majority of things went perfectly to plan.

Matthew Garrett: My free software will respect users or it will be bullshit

I had dinner with a friend this evening and ended up discussing the FSF's four freedoms. The fundamental premise of the discussion was that the freedoms guaranteed by free software are largely academic unless you fall into one of two categories - someone who is sufficiently skilled in the arts of software development to examine and modify software to meet their own needs, or someone who is sufficiently privileged[1] to be able to encourage developers to modify the software to meet their needs.

The problem is that most people don't fall into either of these categories, and so the benefits of free software are often largely theoretical to them. Concentrating on philosophical freedoms without considering whether these freedoms provide meaningful benefits to most users risks these freedoms being perceived as abstract ideals, divorced from the real world - nice to have, but fundamentally not important. How can we tie these freedoms to issues that affect users on a daily basis?

In the past the answer would probably have been along the lines of "Free software inherently respects users", but reality has pretty clearly disproven that. Unity is free software that is fundamentally designed to tie the user into services that provide financial benefit to Canonical, with user privacy as a secondary concern. Despite Android largely being free software, many users are left with phones that no longer receive security updates[2]. Textsecure is free software but the author requests that builds not be uploaded to third party app stores because there's no meaningful way for users to verify that the code has not been modified - and there's a direct incentive for hostile actors to modify the software in order to circumvent the security of messages sent via it.

We're left in an awkward situation. Free software is fundamental to providing user privacy. The ability for third parties to continue providing security updates is vital for ensuring user safety. But in the real world, we are failing to make this argument - the freedoms we provide are largely theoretical for most users. The nominal security and privacy benefits we provide frequently don't make it to the real world. If users do wish to take advantage of the four freedoms, they frequently do so at a potential cost of security and privacy. Our focus on the four freedoms may be coming at a cost to the pragmatic freedoms that our users desire - the freedom to be free of surveillance (be that government or corporate), the freedom to receive security updates without having to purchase new hardware on a regular basis, the freedom to choose to run free software without having to give up basic safety features.

That's why projects like the GNOME safety and privacy team are so important. This is an example of tying the four freedoms to real-world user benefits, demonstrating that free software can be written and managed in such a way that it actually makes life better for the average user. Designing code so that users are fundamentally in control of any privacy tradeoffs they make is critical to empowering users to make informed decisions. Committing to meaningful audits of all network transmissions to ensure they don't leak personal data is vital in demonstrating that developers fundamentally respect the rights of those users. Working on designing security measures that make it difficult for a user to be tricked into handing over access to private data is going to be a necessary precaution against hostile actors, and getting it wrong is going to ruin lives.

The four freedoms are only meaningful if they result in real-world benefits to the entire population, not a privileged minority. If your approach to releasing free software is merely to ensure that it has an approved license and throw it over the wall, you're doing it wrong. We need to design software from the ground up in such a way that those freedoms provide immediate and real benefits to our users. Anything else is a failure.

(title courtesy of My Feminism will be Intersectional or it will be Bullshit by Flavia Dzodan. While I'm less angry, I'm solidly convinced that free software that does nothing to respect or empower users is an absolute waste of time)

[1] Either in the sense of having enough money that you can simply pay, having enough background in the field that you can file meaningful bug reports or having enough followers on Twitter that simply complaining about something results in people fixing it for you

[2] The free software nature of Android often makes it possible for users to receive security updates from a third party, but this is not always the case. Free software makes this kind of support more likely, but it is in no way guaranteed.

comment count unavailable comments

23 September 2014

Dirk Eddelbuettel: RcppArmadillo 0.4.450.1.0

Continuing with his standard pace of approximately one new version per month, Conrad released a new minor release of Armadillo a few days ago. As before, I had created a GitHub-only pre-release which was tested against all eighty-seven (!!) CRAN dependents of our RcppArmadillo package and then uploaded RcppArmadillo 0.4.450.0 to CRAN. The CRAN maintainers pointed out that under the R-development release, a NOTE was issued concerning the C-library's rand() call. This is a pretty new NOTE, but it means using the (sometimes poor quality) rand() generator is now a no-no. Now, Armadillo being as robustly engineered as it is offers a new random number generator based on C++11 as well as a fallback generator for those unfortunate enough to live with an older C++98 compiler. (I would like to note here that I find Conrad's continued support for both C++11, offering very useful modern language idioms, as well as the fallback code for continued deployment and usage by those constrained in their choice of compilers rather exemplary --- because contrary to what some people may claim, it is not a matter of one or the other. C++ always was, and continues to be, a multi-paradigm language which can be supported easily by several standard. But I digress...) In any event, one cannot argue with CRAN about their prescription of a C++98 compiler. So Conrad and I discussed this over email, and came up with a scheme where a user-package (such as RcppArmadillo) can provide an alternate generator which Armadillo then deploys. I implemented a first solution which was then altered / reflected by Conrad in a revised version 4.450.1 of Armadillo. I packaged, and now uploaded, that version as RcppArmadillo 0.4.450.1.0 to both CRAN and into Debian. Besides the RNG change already discussed, this release brings a few smaller changes from the Armadillo side. These are detailed below in the extract from the NEWS file. On the RcppArmadillo side, we now have support for pkgKitten which is both very exciting and likely the topic of another blog post with an example of creating an RcppArmadillo package that purrs. In the process, I overhauled and polished how new packages are created by RcppArmadillo.package.skeleton(). An upcoming blog post may provide an example.
Changes in RcppArmadillo version 0.4.450.1.0 (2014-09-21)
  • Upgraded to Armadillo release Version 4.450.1 (Spring Hill Fort)
    • faster handling of matrix transposes within compound expressions
    • expanded symmatu()/symmatl() to optionally disable taking the complex conjugate of elements
    • expanded sort_index() to handle complex vectors
    • expanded the gmm_diag class with functions to generate random samples
  • A new random-number implementation for Armadillo uses the RNG from R as a fallback (when C++11 is not selected so the C++11-based RNG is unavailable) which avoids using the older C++98-based std::rand
  • The RcppArmadillo.package.skeleton() function was updated to only set an "Imports:" for Rcpp, but not RcppArmadillo which (as a template library) needs only LinkingTo:
  • The RcppArmadillo.package.skeleton() function will now prefer pkgKitten::kitten() over package.skeleton() in order to create a working package which passes R CMD check.
  • The pkgKitten package is now a Suggests:
  • A manual page was added to provide documentation for the functions provided by the skeleton package.
  • A small update was made to the package manual page.
Courtesy of CRANberries, there is also a diffstat report for the most recent release. As always, more detailed information is on the RcppArmadillo page. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

21 September 2014

Joachim Breitner: Using my Kobo eBook reader as an external eInk monitor

I have an office with a nice large window, but more often than not I have to close the shades to be able to see something on my screen. Even worse: There were so many nice and sunny days where I would have loved to take my laptop outside and work there, but it (a Thinkpad T430s) is simply not usable in bright sun. I have seen those nice eInk based eBook readers, who are clearer the brighter they are. That s what I want for my laptop, and I am willing to sacrifice color and a bit of usability due to latency for being able to work in the bright daylight! So while I was in Portland for DebConf14 (where I guess I felt a bit more like tinkering than otherwise) I bought a Kobo Aura HD. I chose this device because it has a resolution similar to my laptop (1440 1080) and I have seen reports from people running their own software on it, including completely separate systems such as Debian or Android. This week, I was able to play around with it. It was indeed simple to tinker with: You can simply copy a tarball to it which is then extracted over the root file system. There are plenty of instructions online, but I found it easier to take them as inspiration and do it my way with basic Linux knowledge that s possible. This way, I extended the system boot script with a hook to a file on the internal SD card, and this file then runs the telnetd daemon that comes with the device s busybox installation. Then I just have to make the device go online and telnet onto it. From there it is a pretty normal Linux system, albeit without an X server, using the framebuffer directly. I even found an existing project providing a VNC client implementation for this and other devices, and pretty soon I could see my laptop screen on the Kobo. Black and white worked fine, but colors and greyscales, including all anti-aliased fonts, were quite broken. After some analysis I concluded that it was confusing the bit pattern of the pixels. Luckily kvncclient shares that code with koreader, which worked fine on my device, so I could copy some files and settings from there et voil : I now have an eInk monitor for my laptop. As a matter of fact, I am writing this text with my Kobo sitting on top of the folded-back laptop screen! I did some minor adjustments to my laptop: All this is still very manual (going online with the kobo, finding its IP address, logging in via telnet, killing the Kobo's normal main program, starting x11vnc, finding my ip address, starting the vnc client, doing the adjustments mentioned above), so I need to automate it a bit. Unfortunately, there is no canonical way to extend the Kobo by your own application: The Kobo developers made their device quite open, but stopped short from actually encouraging extensions, so people have created many weird ways to start programs on the Kobo dedicated start menus, background programs observing when the regular Kobo app opens a specific file, complete replacements for the system. I am considering to simply run an SSH server on the device and drive the whole process from the laptop. I ll keep you up-to-date. A dream for the future would be to turn the kobo into a USB monitor and simply connect it to any computer, where it then shows up as a new external monitor. I wonder if there is a standard for USB monitors, and if it is simple enough (but I doubt it). A word about the kobo development scene: It seems to be quite active and healthy, and a number of interesting applications are provided for it. But unfortunately it all happens on a web forum, and they use it not only for discussion, but also as a wiki, a release page, a bug tracker, a feature request list and as a support line often on one single thread with dozens of posts. This makes it quite hard to find relevant information and decide whether it is still up-to-date. Unfortunately, you cannot really do without it. The PDF viewer that comes with the kobo is barely okish (e.g. no crop functionality), so installing, say, koreader is a must if you read more PDFs than actual ebooks. And then you have to deal with the how-to-start-it problem. That reminds me: I need to find a decent RSS reader for the kobo, or possibly a good RSS-to-epub converter that I can run automatically. Any suggestions? PS and related to this project: Thanks to Kathey!

Dariusz Dwornikowski: statistics of RFS bugs and sponsoring process

For some days I have been working on statistics of the sponsoring process in Debian. I find this to be one of the most important things that Debian has to attract and enable new contributions. It is important to know how this process works, whether we need more sponsors, how effective is the sponsoring and what are the timings connected to it. How I did this ? I have used Debbugs SOAP interface to get all bugs that are filed against sponsorship-requests pseudo package. SOAP gives a little bit of overhead because it needs to download a complete list of bugs for the sponsorship-requests package, and then process them according to given date ranges. The same information can be easily extracted from the UDD database in the future, it will be faster because SQL is better when working with date ranges than python obviously. The most problematic part was getting the "real done date" of a particular bug, and frankly most of my time I have spent on writing a rather dirty and complicated script. The script gets a log for a particular bug number and returns a "real done date". I have published a proof of concept in a previous post.. What I measured ? RFSs is a queue, and in every queue one is interested in a mean time to get processed. In this case I called the metric global MTTGS (mean time to get sponsored). This is a metric that gives the overall performance insight in RFS queue. Time to get sponsored (TTGS) for a bug is a number of days that passed between filing an RFS bug and closing it (bug was sponsored). Mean time to get sponsored is calculated as a sum of TTGSs of all bugs divided by number of bugs (in a given period of time). Global MTTGS is MTTGS calculated for a period of time 2012-1-1 until today(). Besides MTTGS I have also measured typical bug related metrics: Plots and graphs Below is a plot of global MTTGS vs. time (click for a larger image). mttgs plot As you can see, the trend is roughly exponential and MTTGS tends to settle around 60 days at the end of the year 2013. This does not mean that your package will wait 60 days on average nowadays to get sponsored. I remind that this is a global MTTGS, so even if the MTTGS of last month was very low, the global MTTGS would decrease just slightly. It gives, however, a good glance in performance of the process. Even that more packages are filed for sponsoring (see next graphs) now, than in the beginning of the epoch, the sponsoring rate is high enough to flatten the global MTTGS, and with time maybe decrease it. The image below (click for a larger one) shows how many bugs reside in a queue with status open or closed (calculated for each day). For closed we have an almost linear function, so each day more or less the same amount of bugs are closed and they increase the pool of bugs with status closed. For bugs with status open the interesting part begins around May 2012 after the system is saturated or gets popular. It can be interpreted as a plot of how many bugs reside in the queue, the important part is that it is stable and does not show clear increasing trend. open done plot The last plot shows arrival and departure rate of bugs from RFS queue, i.e. how many bugs are opened and closed each day. The interesting part here are the maxima. Let's look at them. opened closed plot Maximal number of opened bugs (21) was on 2012-05-06. As it appears it was a bunch upload of RFSs for tryton-modules-*.. 
  706953  RFS: tryton-modules-account-stock-anglo-saxon/2.8.0-1 
  706954  RFS: tryton-modules-purchase-shipment-cost/2.8.0-1 
  706948  RFS: tryton-modules-production/2.8.0-1 
  706969  RFS: tryton-modules-account-fr/2.8.0-1 
  706946  RFS: tryton-modules-project-invoice/2.8.0-1 
  706950  RFS: tryton-modules-stock-supply-production/2.8.0-1 
  706942  RFS: tryton-modules-product-attribute/2.8.0-1 
  706957  RFS: tryton-modules-stock-lot/2.8.0-1 
  706958  RFS: tryton-modules-carrier-weight/2.8.0-1 
  706941  RFS: tryton-modules-stock-supply-forecast/2.8.0-1 
  706955  RFS: tryton-modules-product-measurements/2.8.0-1 
  706952  RFS: tryton-modules-carrier-percentage/2.8.0-1 
  706949  RFS: tryton-modules-account-asset/2.8.0-1 
  706904  RFS: chinese-checkers/0.4-1 
  706944  RFS: tryton-modules-stock-split/2.8.0-1 
  706981  RFS: distcc/3.1-6 
  706945  RFS: tryton-modules-sale-supply/2.8.0-1 
  706959  RFS: tryton-modules-carrier/2.8.0-1 
  706951  RFS: tryton-modules-sale-shipment-cost/2.8.0-1 
  706943  RFS: tryton-modules-account-stock-continental/2.8.0-1 
  706956  RFS: tryton-modules-sale-supply-drop-shipment/2.8.0-1
Maximum number of closed bugs (18) was on 2013-09-24, and as you probably guessed right also tryton modules had impact on that. 
  706953  RFS: tryton-modules-account-stock-anglo-saxon/2.8.0-1 
  706954  RFS: tryton-modules-purchase-shipment-cost/2.8.0-1 
  706948  RFS: tryton-modules-production/2.8.0-1 
  706969  RFS: tryton-modules-account-fr/2.8.0-1 
  706946  RFS: tryton-modules-project-invoice/2.8.0-1 
  706950  RFS: tryton-modules-stock-supply-production/2.8.0-1 
  706942  RFS: tryton-modules-product-attribute/2.8.0-1 
  706958  RFS: tryton-modules-carrier-weight/2.8.0-1 
  706941  RFS: tryton-modules-stock-supply-forecast/2.8.0-1 
  706955  RFS: tryton-modules-product-measurements/2.8.0-1 
  706952  RFS: tryton-modules-carrier-percentage/2.8.0-1 
  706949  RFS: tryton-modules-account-asset/2.8.0-1 
  706944  RFS: tryton-modules-stock-split/2.8.0-1 
  706959  RFS: tryton-modules-carrier/2.8.0-1 
  723991  RFS: mapserver/6.4.0-2 
  706951  RFS: tryton-modules-sale-shipment-cost/2.8.0-1 
  706943  RFS: tryton-modules-account-stock-continental/2.8.0-1 
  706956  RFS: tryton-modules-sale-supply-drop-shipment/2.8.0-1
The software Most of the software was written in Python. Graphs were generated in R. After a code cleanup I will publish a complete solution on my github account, free to use by everybody. If you would like to see another statistics, please let me know, I can create them if the data provides sufficient information.

16 September 2014

Matthew Garrett: ACPI, kernels and contracts with firmware

ACPI is a complicated specification - the latest version is 980 pages long. But that's because it's trying to define something complicated: an entire interface for abstracting away hardware details and making it easier for an unmodified OS to boot diverse platforms.

Inevitably, though, it can't define the full behaviour of an ACPI system. It doesn't explicitly state what should happen if you violate the spec, for instance. Obviously, in a just and fair world, no systems would violate the spec. But in the grim meathook future that we actually inhabit, systems do. We lack the technology to go back in time and retroactively prevent this, and so we're forced to deal with making these systems work.

This ends up being a pain in the neck in the x86 world, but it could be much worse. Way back in 2008 I wrote something about why the Linux kernel reports itself to firmware as "Windows" but refuses to identify itself as Linux. The short version is that "Linux" doesn't actually identify the behaviour of the kernel in a meaningful way. "Linux" doesn't tell you whether the kernel can deal with buffers being passed when the spec says it should be a package. "Linux" doesn't tell you whether the OS knows how to deal with an HPET. "Linux" doesn't tell you whether the OS can reinitialise graphics hardware.

Back then I was writing from the perspective of the firmware changing its behaviour in response to the OS, but it turns out that it's also relevant from the perspective of the OS changing its behaviour in response to the firmware. Windows 8 handles backlights differently to older versions. Firmware that's intended to support Windows 8 may expect this behaviour. If the OS tells the firmware that it's compatible with Windows 8, the OS has to behave compatibly with Windows 8.

In essence, if the firmware asks for Windows 8 support and the OS says yes, the OS is forming a contract with the firmware that it will behave in a specific way. If Windows 8 allows certain spec violations, the OS must permit those violations. If Windows 8 makes certain ACPI calls in a certain order, the OS must make those calls in the same order. Any firmware bug that is triggered by the OS not behaving identically to Windows 8 must be dealt with by modifying the OS to behave like Windows 8.

This sounds horrifying, but it's actually important. The existence of well-defined[1] OS behaviours means that the industry has something to target. Vendors test their hardware against Windows, and because Windows has consistent behaviour within a version[2] the vendors know that their machines won't suddenly stop working after an update. Linux benefits from this because we know that we can make hardware work as long as we're compatible with the Windows behaviour.

That's fine for x86. But remember when I said it could be worse? What if there were a platform that Microsoft weren't targeting? A platform where Linux was the dominant OS? A platform where vendors all test their hardware against Linux and expect it to have a consistent ACPI implementation?

Our even grimmer meathook future welcomes ARM to the ACPI world.

Software development is hard, and firmware development is software development with worse compilers. Firmware is inevitably going to rely on undefined behaviour. It's going to make assumptions about ordering. It's going to mishandle some cases. And it's the operating system's job to handle that. On x86 we know that systems are tested against Windows, and so we simply implement that behaviour. On ARM, we don't have that convenient reference. We are the reference. And that means that systems will end up accidentally depending on Linux-specific behaviour. Which means that if we ever change that behaviour, those systems will break.

So far we've resisted calls for Linux to provide a contract to the firmware in the way that Windows does, simply because there's been no need to - we can just implement the same contract as Windows. How are we going to manage this on ARM? The worst case scenario is that a system is tested against, say, Linux 3.19 and works fine. We make a change in 3.21 that breaks this system, but nobody notices at the time. Another system is tested against 3.21 and works fine. A few months later somebody finally notices that 3.21 broke their system and the change gets reverted, but oh no! Reverting it breaks the other system. What do we do now? The systems aren't telling us which behaviour they expect, so we're left with the prospect of adding machine-specific quirks. This isn't scalable.

Supporting ACPI on ARM means developing a sense of discipline around ACPI development that we simply haven't had so far. If we want to avoid breaking systems we have two options:

1) Commit to never modifying the ACPI behaviour of Linux.
2) Exposing an interface that indicates which well-defined ACPI behaviour a specific kernel implements, and bumping that whenever an incompatible change is made. Backward compatibility paths will be required if firmware only supports an older interface.

(1) is unlikely to be practical, but (2) isn't a great deal easier. Somebody is going to need to take responsibility for tracking ACPI behaviour and incrementing the exported interface whenever it changes, and we need to know who that's going to be before any of these systems start shipping. The alternative is a sea of ARM devices that only run specific kernel versions, which is exactly the scenario that ACPI was supposed to be fixing.

[1] Defined by implementation, not defined by specification
[2] Windows may change behaviour between versions, but always adds a new _OSI string when it does so. It can then modify its behaviour depending on whether the firmware knows about later versions of Windows.

comment count unavailable comments

15 September 2014

Thomas Goirand: Backporting libjs-angularjs and libjs-d3 to Wheezy

If you didn t notice, Javascript isn t as simple as it used to be Want to backport the 2 simple javascript libs? No problem. You then just need to backport a bunch of other packages which are build-dependencies (and file #761670, #761672, and #761674 on the way when rebuilding ). Here s the short list: 
gyp
node-abbrev
node-ansi
node-ansi-color-table
node-archy
node-async
node-block-stream
node-combined-stream
node-contextify
node-cookie-jar
node-cssom
node-delayed-stream
node-diff
node-eyes
node-forever-agent
node-form-data
node-fstream
node-fstream-ignore
node-github-url-from-git
node-glob
node-graceful-fs
node-gyp
node-htmlparser
node-inherits
node-ini
node-jake
node-jsdom
node-json-stringify-safe
node-lockfile
node-lru-cache
node-marked
node-mime
node-minimatch
node-mkdirp
node-mute-stream
node-node-uuid
node-nopt
node-normalize-package-data
node-npmlog
node-once
node-optimist
node-osenv
node-qs
node-queue-async
node-read
node-read-package-json
node-request
node-retry
node-rimraf
node-semver
node-sha
node-sigmund
node-slide
node-smash
node-tar
node-tunnel-agent
node-uglify
node-underscore
node-utilities
node-vows
node-whic
node-which
node-wordwrap
nodejs
npm
ruby-ronn
Yes, that s 66 packages above And of course, backporting some ruby stuff makes sense :)

Vincent Sanders: NetSurf 3.2

We recently released a new version of NetSurf this was largely to address numerous small bugs but did also include the persistent caching implementation I have written about previously. A release used to require the release manager (usually me) to perform a lot of manual processes and while we had a checklist it was far too easy to miss things.

The Continuous Integration (CI) system combined with signed release tags in git has resulted in a greatly simplified process indeed it has become almost completely automated. The majority of the manual work is now confined to doing the tasks that require actual decision making and checking we are releasing what was intended.

By having the CI system build release binaries the project now has a much clearer and importantly traceable process, I can recommend such a system to any project that produces releases especially if they release binaries for any of their targets.

I have also managed to package and upload this version of NetSurf ready for the Debian Jessie release. I would like to thank Jonathan Wiltshire for his assistance in ensuring this was a good quality package.

The release incorporates the successfully merged work of Rupinder Singh who was our our GSoc 2014 student. Rupinder mainly made improvements to our core DOM implementation and was very responsive and enthusiastic throughout his time despite the mentor team sometimes not being available.

This work goes towards improving NetSurf in the future by ensuring the underlying features are present in our core libraries. The GSoc mentors and all project developers are all pleased with the results of this years GSoc participation and would like to thank everyone involved in making our participation possible.

Along with the good news comes a little bad:
PowerPC Mac OS X
Despite repeated calls for assistance with new hardware and Java builds none has been forthcoming meaning that from this release we ware no longer able to ship PowerPC builds for MAC OS X.

The main issue is the last version of MAC OS X that runs on PPC is Leopard and there is no viable Java 1.6 port necessary for our CI system to run. Additionally the fully loaded PPC Mac mini (kindly donated to us by Mythic Beasts) had become far too slow to keep up with our builds and was causing long delays.
Bugs
NetSurf 3.2 Bug graph
We have a lot of bugs, in fact just during this release cycle we have 30 more bugs reported than we closed.So while the new bug reporting system has been a success and our users are reporting issues when they find them the development team is not keeping up..

The failure to keep up stems from the underlying issue of lack of manpower. We have relatively few active developers which is especially problematic when there are many users for a platform, such as RISCOS, but the maintainer is unable to commit enough time to fixing issues.

If you would like to help making NetSurf a better browser we are always happy to work with new contributors.

Cyril Brulebois: Freelance Debian consultant

I m not used to talking about my day job but here s an exception. Over the past few years I worked in two startups (3 years each). It was nice to spend time in different areas: one job was mostly about research and development in a Linux cluster environment; the other one was about maintaining a highly-customized, Linux-based operating system, managing a small support team, and performing technological surveillance in IT security. In the meanwhile I ve reached a milestone: 10 years with Debian. I had been wondering for a few months whether I could try my luck going freelance, becoming a Debian consultant. I finally decided to go ahead and started in August! The idea is to lend a hand for various Debian-related things like systems administration, development/debugging, packaging/repository maintenance, or Debian Installer support, be it one-shot or on a regular basis. I didn t think about trainings/workshops at first but sharing knowledge is something I ve always liked, even if I didn t become a teacher. For those interested, details can be found on my website: https://mraw.org/. Of course this doesn t mean I m going to put an end to my volunteer activities within Debian, especially as a Debian Installer release manager. Quite the contrary in fact! See the August and September debian-boot@ archives, which have been busy months. :)

Gergely Nagy: Looking ahead

A little more than a year ago, I started working as a syslog-ng OSE developer full-time. That was a tremendously important milestone in my career, as one of the goals I wanted to achieve in life - to work on free software for a living - became a reality. Rocket boots were fired up, and we accomplised quite a lot in the past year, and I'm very, very proud of the work we did - we, the whole community. I enjoyed every bit of it, but as it turns out, some of the other desires I wish to pursue, and new challenges I am looking for, will lead me in a different direction. At the end of August, I handed in my resignation, and the past friday was my last work day at BalaBit.There are a few questions that will likely be asked, and I'll try my best to answer them beforehand. Questions such as: What will happen to syslog-ng?, Who will be the new maintainer?, How does this affect your Debian work?, and so on, and so forth.syslog-ngWhat will happen to syslog-ng?After careful consideration, with the syslog-ng team at BalaBit, we decided that they will take over OSE-related responsibilities as well. They will do releases, they will engage the people on GitHub and the mailing list, they will take care of the @sngOSE twitter account.During the past few months, we've been working on pushing the team closer to the community: we moved issues to GitHub, the team submitted pull requests, and in general, we moved closer to each other in every possible way.While they may not have the open source maintainer experience I had, they are all capable folk, and will quickly learn on the job. The team taking over also has the advantage of having more manpower, and better collaboration between the premium edition and OSE.Who will be the syslog-ng maintainer?There will be no single bottle neck. This has both good and bad implications, but I believe the good ones outweigh the disadvantages.What about the roadmap? When will 3.6.1 happen?The roadmap is already laid out for 3.6, but it is the team's judgement when it will be released. The latest 3.6.0beta2 was released together with the team, too. I expect there will be delays (I planned 3.6.1 to be released on September 27th), but not much; a few weeks, perhaps.What will your involvement in syslog-ng development be?With changing jobs, my involvement will drastically decrease. I will remain a syslog-ng user, and I will continue packaging it for Debian and Ubuntu, and will keep my unofficial repository running. I do not see myself contributing much, perhaps bug reports, opinions and an occasional idea.Nevertheless, my expertise is still considerable, and I will help the team and the community in whatever way I can - but I will be severely time constrained.DebianWhile BalaBit were very free software friendly, and allowed me to work on Debian tasks from time to time, my other activities took up an increasingly big chunk of my paid time, and I had to cut back a little. At the new job, things will be a bit different: while I won't have as much time to do Debian work on the job, I will have a lot more free time, in which I hope to do more for Debian.I will - as promised above - continue maintaining syslog-ng, and all other packages I currently maintain. Apart from those, I wish to make myself more useful within the Clojure and Hy teams.MiscellaneousWhere to are you moving?This is something I will answer in due time. For now, I will have two weeks off, which I wish to spend my way, picking up projects I neglected for far too long.

12 September 2014

John Goerzen: The Thrill and Stress of Too Many Hobbies

Today, 4PM. Jacob and Oliver excitedly peer at the box in our kitchen a really big box, taller than them. Inside is is the first model airplane I d ever purchased. The three of us hunkered down on the kitchen floor, opened the box, unpacked the parts, examined the controller, and found the manual with cryptic assembly directions. Oliver turned some screws while Jacob checked out the levers on the controllers. Then they both left for a bit to play with their toy buses. A little while later, the three of us went outside. It was too windy to fly. I had never flied an RC plane before only RC quadcopters (much easier to fly), and some practice time on an RC simulator. But the excitement was too much. So out we went, and the plane took off perfectly, climbed, flew over the trees, and circled above our heads at my command. I even managed a good landing in the wind, despite about 5 aborted attempts due to coming in too high, wrong angle, too fast, or last-minute gusts of wind throwing everything off. I am not sure how I pulled that all off on my first flight, but somehow I did! It was thrilling! I ve had a lot of hobbies in my life. Computers have run through many of them; I learned Pascal (a programming language) at about the same time I learned cursive handwriting and started with C at around age 10. It was all fun. I ve been a Debian developer for some 18 years now, and have written a lot of code, and even books about code, over the years. Photography, music, literature, history, philosophy, and theology have been interests for quite some time as well. In the last few years, I ve picked up amateur radio, model aircraft, etc. And last month, Laura led me into Ada s Technical Books during our visit to Seattle, resulting in me getting interested in Arduino. (The boys and I have already built a light-activated crossing gate for their HO-gauge model trains, and Jacob can now say he s edited a few characters of C!) Sometimes I find ways to merge hobbies; I ve set up all sorts of amateur radio systems on Linux, take aerial photographs, and set up systems to stream music in my house. But I also have a lot less time for hobbies overall than I once did; other things in life, such as my children, are more important. Some of the code I once worked on actively I no longer use or maintain, and I feel guilty about that when people send bug reports that I have no interest in fixing anymore. Sometimes I feel a need to cut down, and perhaps have; and then, I get an interest in RC aircraft and find an airplane that is great for a beginner and fairly inexpensive. Perhaps it is the curse of being a curious person living in an interesting world. Do any of the rest of you have a large number of hobbies? How do you feel about that?

11 September 2014

Enrico Zini: suspend-i-really-mean-it

Laptop, I demand that you suspend! Dear Lazyweb, Sometimes some application prevents suspend on my laptop. I want to disable that feature: how? I understand that there may exist some people who like that feature. I, on the other hand, consider a scenario like this inconceivable:
  1. I'm on a plane working with my laptop, the captain announces preparations for landing, so I quickly hit the suspend button (or close the lid) on my laptop and stow it away.
  2. One connecting flight later, I pick up my backpack, I feel it unusually hot and realise that my laptop has been on all along, and is now dead from either running out of battery or thermal protection.
  3. I think things that, if spoken aloud in front of a pentacle, might invoke major lovecraftian horrors.
I do not want this scenario to ever be possible. I want my suspend button to suspend the laptop no matter what. If a process does not agree, I'm fine with suspending it anyway, or killing it. If I want my laptop to suspend, I generally have a good enough real-world reason for it, and I cannot conceive that a software could ever be allowed to override my command. How do I change this? I don't know if I should look into systemd, upowerd, pm-utils, the kernel, the display manager or something else entirely. I worry that I cannot even figure where to start looking for a solution. This happened to me multiple times already, and I consider it ridiculous. I know that it can cause me data loss. I know that it can cause me serious trouble in case I was relying on having some battery or state left at my arrival. I know that depending on what is in my backpack, this could also be physically dangerous. So, what knob do I tweak for this? How do I make suspend reliable? Update Systemd has an inhibitor system, and systemd-inhibit --list only lists 'delay' blocks in my system. It is an interesting feature that seems to be implemented in the right way, and it could mean that I finally can get my screen to be locked before the system is suspended. It is possible to configure the inhibitor system in /etc/systemd/logind.conf, including ways to ignore inhibitors, and a maximum time after which inhibitors are ignored if not yet released. Try as I might to run everything that I was running on the plane that time, I could not manage to see anything take an inhibitor block that could have prevented my suspend. I now suspect that what happened to me was a glitch caused by something else (hardware? kernel? cosmic rays!) during that specific suspend. When I had this issue in the past it looks like the infrastructure at the time was far more primitive that what we have now with systemd, so I guess that when writing my blog post I had simply correlated my old experiences with a one-off suspend glitch. If I want to investigate or tune further, to test the situation with a runaway block, I can use commands like systemd-inhibit --mode=block sleep 3600. I'm quite happy to see that we're moving to a standard and sane system for this. In the meantime, I have learnt that pm-utils has now become superfluous and can be deinstalled, and so can acpi-support and acpi-support-base. Thanks vbernat, mbiebl, and ah, on #debian-devel for all the help.

Sylvestre Ledru: Rebuild of Debian using Clang 3.5.0

Clang 3.5.0 has just been released. A new rebuild has been done highlight the progress to get Debian built with clang. tl;dr: Great progress. We decreased from 9.5% to 5.7% of failures. Full results are available on http://clang.debian.net At time of the rebuild with 3.4.2, we had 2040 packages failing to build with clang. With 3.5.0, this dropped to 1261 packages. Fixes With Arthur Marble and Alexander Ovchinnikov, both GSoC students, we worked on various ways to decrease the number of errors. Upstream fixes First, the most obvious way, we fixed programming bugs/mistakes in upstream sources. Basically, we took categories of failure and fixed issues one after the other. We started with simple bugs like 'Wrong main declaration', 'non-void function should return a value' or 'Void function should not return a value'.

They are trivial to fix. We continued with harder fixes like ' Undefined reference' or 'Variable length array for a non POD (plain old data) element'.

So, besides these one, we worked on:
In total, we reported 295 bugs with patches. 85 of them have been fixed (meaning that the Debian maintainer uploaded a new version with the fix).

In parallel, I think that the switch by FreeBSD and Mac OS X to Clang also helped to fix various issues by upstreams. Hacking in clang As a parallel approach, we started to implement a suggestion from Linus Torvalds and a few others. Instead of trying to fix all upstream, where we can, we tried to update clang to improve the gcc compatibility.

gcc has many flags to disable or enable optimizations. Some of them are legacy, others have no sense in clang, etc. Instead of failing in clang with an error, we create a new category of warnings (showing optimization flag '%0' is not supported) and moved all relevant flags into it. Some examples, r212805, r213365, r214906 or r214907

We also updated clang to silent some useless arguments like -finput_charset=UTF-8 (r212110), clang being UTF-8 compliant.

Finally, we worked on the forwarding of linker flags. Clang and gcc have a very different behavior: when gcc does not know an argument, it is going to forward the argument to the linker. Clang, in this case, is going to reject the argument and fail with an error. In clang, we have to explicitly declare which arguments are going to be transfer to the linker. Of course, the correct way to pass arguments to the linker is to use -Xlinker or -Wl but the Debian rebuild proved that these shortcuts are used. Two of these arguments are now forwarded: New errors Just like in other releases, new warnings are added in clang. With (bad) usage of -Werror by upstream software, this causes new build failures: I also took the opportunity to add some further categorizations in the list of errors. Some examples: Next steps The Debile project being close to ready with Cl ment Schreiner's GSoC, we will now have an automatic and transparent way to rebuild packages using clang. Conclusion As stated, we can see a huge drop in term of number of failures over time:
Hopefully, Clang getting better and better, more and more projects adopting it as the default compiler or as a base for plugin/extension developments, this percentage will continue to decrease.
Having some kind of release goal with clang for Jessie+1 can now be considered as potentially reachable. Want to help? There are several things which can be done to help: Acknowledgments Thanks to David Suarez for the rebuilds of the archive, Arthur Marble and Alexander Ovchinnikov for their GSoC works and Nicolas S velin-Radiguet for the few fixes.
Original post blogged on b2evolution.

Matthias Klumpp: Listaller: Back to the future!

Listaller-Logo (with text)It is time for another report on Listaller, the cross-distro 3rd-party package installer, which is now in development for depending how you count 5-6 years. This will become a longer post, so you might grab some coffee or tea ;-) The original idea The Listaller project was initially started with the goal to make application deployment on Linux distributions as simple as possible, by providing a unified package installation format and tools which make building apps for multiple distributions easier and deployment of updates simple. The key ideas were: The current state The current release of Listaller handles all of this with a plugin for PackageKit, the cross-distro package-management abstraction layer. It hooks into PackageKit and reads information passing through to the native distributor backend, and if it encounters Listaller software, it handles it appropriately. It can also inject update information. This results in all Listaller software being shown in any PackageKit frontends, and people can work with it just like if the packages were native packages. Listaller package installations are controlled by a machine policy, so the administrator can decide that e.g. only packages from a trusted source (= GPG signature in trusted database) can be installed. Dependencies can be pulled from the distributor s repositories, or optionally from external sources, like the PyPI. This sounds good on paper, but the current implementation has various problems. The issues The current Listaller approach has some problems. The biggest one lies in the future: Soon, there will be no PackageKit plugins anymore! PackageKit 1.0 will remove support for them, because they appear to be a major source for crashes, even the in-tree plugins cause problems. Also, the PackageKit service itself is currently being trimmed of unneeded features and less-used code. These changes in PackageKit are great and needed for the project (and I support these efforts), but they cause a pretty huge problem for Listaller: The project relies on the PackageKit plugin if used without it, you loose the system-integration part, which is one of the key concepts of Listaller, and a primary goal. But this issue is not the only one. There are more. One huge problem for Listaller is dependency-solving: It needs to know where to get software from in case it isn t installed already. And that has to be done in a cross-distributional way. This is an incredibly complex task, and Listaller contains lots of workarounds for various quirks. It contains so much hacks for distro-specific stuff, that it became really hard to understand. The Listaller dependency model also became very complex, because it tried to handle many corner-cases. This is bad, of course. But the workarounds weren t added for fun, but because it was assumed to be easier than to fixing the root cause, which would have required collaboration between distributors and some changes on the stack, which seemed unlikely to happen at the time the code was written. The systemd effort Also a thing which affects Listaller, is the latest push from the systemd team to allow cross-distro 3rd-party installations to happen. I definitively recommend reading the linked blogpost from Lennart, if you have some spare time! The identified problems are the same as for Listaller, but the solution they propose is completely different, and about three orders of magnitude more invasive than whatever the Listaller project had in mind (I make these numbers up, so don t ask!). There are also a few issues I see with Lennarts approach, I will probably go into detail about that in another blogpost (e.g. it requires multiple copies of a library lying around, where one version might have a security vulnerability, and another one doesn t it s hard to ensure everything is up to date and secure that way, even if you have a top-notch sandbox). I have great respect for the systemd crew and especially Lennart, and I hope them to succeed with their efforts. However, I also think Listaller can achieve a similar things with a less-invasive solution, at least for the 3rd-party app-installations (Listaller is one of the partial-fix solutions with strict focus, so not a direct competitor to the holistic systemd approach. Both solutions could happily live together.) A step into the future Some might have guessed it already: There are some bigger changes coming to Listaller! The most important one is that there will be no Listaller anymore, at least not in its old form. Since the current code relies heavily on the PackageKit plugin, and contains some ugly workarounds, it doesn t make much sense to continue working on it. Instead, I started the Listaller.NEXT project, which is a rewrite of Listaller in C. There are a some goals for the rewrite: I made a last release of the 0.5.x series of Listaller, to work with PackageKit 0.9.x the future lies in the C port. If you are using Listaller (and I know of people who do, for example some deploy statically-linked stuff on internal test-setups with it), stay tuned. The packaging format will stay mostly compatible with the current version, so you will not see many changes there (the plan is to freeze it very soon, so no backwards-incompatible changes are made anymore). The o.5.x series will receive critical bugfixes if necessary. Help needed! As always, there is help needed! Writing C is not that difficult ;-) But user feedback is welcome as well, in case you have an idea. The new code will be hosted on Github in the new listaller-next branch (currently not that much to find there). Long-term, we will completely migrate away from Launchpad. You can expect more blogposts about the Listaller concepts and progress in the next months (as soon as I am done with some AppStream-related things, which take priority).

9 September 2014

Daniel Pocock: xTupleCon WebRTC talk schedule change, new free event

As mentioned in my earlier blog, I'm visiting several events in the US and Canada in October and November. The first of these, the talk about WebRTC in CRM at xTupleCon, has moved from the previously advertised timeslot to Wednesday, 15 October at 14:15. WebRTC meeting, Norfolk, VA Later that day, there will be a WebRTC/JavaScript meetup in Norfolk hosted at the offices of xTuple. It is not part of xTupleCon and free to attend. Please register using the Eventbrite page created by xTuple. This will be a hands on event for developers and other IT professionals, especially those in web development, network administration and IP telephony. Please bring laptops and mobile devices with the latest versions of both Firefox and Chrome to experience WebRTC. Free software developers at xTupleCon If you do want to attend xTupleCon itself, please contact xTuple directly through this form for details about the promotional tickets for free software developers.

6 September 2014

Joachim Breitner: ICFP 2014

Another on-my-the-journey-back blog post; this time from the Frankfurt Airport Train Station my flight was delayed (if I knew that I could have watched the remaining Lightning Talks), and so was my train, but despite 5min of running through the Airport just not enough. And now that the free 30 Minutes of Railway Station Internet are used up, I have nothing else to do but blog... Last week I was attending ICFP 2014 in Gothenburg, followed by the Haskell Symposium and the Haskell Implementors Workshop. The justification to attend was the paper on Safe Coercions (joint work with Richard Eisenberg, Simon Peyton Jones and Stephanie Weirich), although Richard got to hold the talk, and did so quite well. So I got to leisurely attend the talks, while fighting the jet-lag that I brought from Portland. There were as expected quite a few interesting talks. Among them the first keynote, Kathleen Fisher on the need for formal methods in cars and toy-quadcopters and unmanned battle helicopters, which made me conclude that my Isabelle skills might eventually become relevant in practical applications. And did you know that if someone gains access to your car s electronics, they can make the seat belt pull you back hard? Stefanie Weirich s keynote (and the subsequent related talks by Jan Stolarek and Richard Eisenberg) on what a dependently typed Haskell would look like and what we could use it for was mouth-watering. I am a bit worried that Haskell will be become a bit obscure for newcomers and people that simply don t want to think about types too much, on the other hand it seems that Haskell as we know it will always stay there, just as a subset of the language. Similarly interesting were refinement types for Haskell (talks by Niki Vazou and by Eric Seidel), in the form of LiquidTypes, something that I have not paid attention to yet. It seems to be a good way for more high assurance in Haskell code. Finally, the Haskell Implementors Workshop had a truckload of exciting developments in and around Haskell: More on GHCJS, Partial type signatures, interactive type-driven development like we know it from Agda, the new Haskell module system and amazing user-defined error messages the latter unfortunately only in Helium, at least for now. But it s not the case that I only sat and listened. During the Haskell Implementors Workshop I held a talk Contributing to GHC with a live demo of me fixing a (tiny) bug in GHC, with the aim of getting more people to hack on GHC (slides, video). The main message here is that it is not that big of deal. And despite me not actually saying much interesting in the talk, I got good feedback afterwards. So if it now actually motivates someone to contribute to GHC, I m even more happier. And then there is of course the Hallway Track. I discussed the issues with fusing a left fold (unfortunately, without a great solution). In order to tackle this problem more systematically, John Wiegley and I created the beginning of a List Fusion Lab , i.e. a bunch of list benchmark and the possibility to compare various implementations (e.g. with different RULES) and various compilers. With that we can hopefully better assess the effect of a change to the list functions. PS: The next train is now also delayed, so I ll likely miss my tram and arrive home even later... PPS: I really have to update my 10 year old picture on my homepage (or redesign it completely). Quite a few people knew my name, but expected someone with shoulder-long hair... PPPS: Haskell is really becoming mainstream: I just talked to a randomly chosen person (the boy sitting next to me in the train), and he is a Haskell enthusiast, building a structured editor for Haskell together with his brother. And all that as a 12th-grader...

4 September 2014

Adnan Hodzic: Debian PPA Utility

Debian remains to be my favorite distribution, however there s one thing that s missing, that thing is called PPA. There were numerous discussions on this topic inside of Debian, but AFAIK without any visible movement. Thus, I decided to publish a utility I ve been using for some time now. PPA s Since its introduction, PPA s are exclusively connected to Ubuntu and its derivatives (Mint, Elementary, etc ). But over time, a number of interesting projects appeared whose whole development is happening inside of PPA s. To name few, I m talking about TLP, Geary, Oracle Java Installer, Elementary OS and etc Some of these projects are in WNPP without much happening for a long time, i.e: TLP One option was to repackage these packages and then have them uploaded to Debian, or just go rogue and install them directly from its PPA s. Title of this post might hint which path I took. In theory, adding Ubuntu packages on your Debian system is a bad idea, and adding its PPA s is probably even worse. But, I ve been using couple (TLP, Geary, couple of custom icon sets) of these PPA s on my personal/work boxes, and to be honest, never had a single problem. Also, setting Pinning priority to low for the PPA you added is never a bad idea. Most of the PPA s I use, are usually fairly simple packages with single binary and dependencies which are found in Debian itself. Of course, I don t recommend adding PPA s on production boxes, or even PPA s such as GNOME3 Team PPA s, but rather add Apt Pinning on your system and fetch those packages directly from Debian. Debian PPA Utility Is a very simple utility, which adds add-apt-repository binary script that allows you to add PPA s on Debian. Code is available on GitHub, it s licensed as GPLv3, so feel free to fork it, improve it, use it and abuse it. How to use it? Download/Build package You can download my signed package (source and changes file are in same directory) Or you can build your own by running "dpkg-buildpackage -uc -us" inside of the debian-ppa source directory. Install/Add PPA s After you install the package, you re able to run add-apt-repository and add PPA s. i,e: sudo add-apt-repository ppa:linrunner/tlp debian ppa utility Currently, Debian PPA Utility only works on >= Wheezy. At this point I have no plans to try pushing this utility into Debian, as I m sure even this blog post will be labelled as heresy by many. Update! It was just pointed to me that add-apt-repository is available in software-properties-common package. However, PPA s added by add-apt-repository binary present in this package instead of adding Ubuntu codename s to your list file, will add Debian codenames which without change will make whole PPA entry useless. I believe codename handling is better in Debian PPA Utility . I admit, my only mistake is, instead of fixing things in software-properties-common package, I made a completely new utility which aims to do the same thing. Added: conflicts/replaces: software-properties-common to debian/control file. Anyway, enjoy!

Next.

Previous.